Magnetotactic bacteria (MTB) belong to several phyla. This class of microorganisms exhibits the ability magneto-aerotaxis. MTB synthesize biominerals in organelle-like structures called magnetosomes, which contain single-domain crystals magnetite (Fe3O4) or greigite (Fe3S4) characterized by a high degree structural and compositional perfection. Magnetosomes from dead could be preserved sediment...

SUMMARY Ferrimagnetic, monoclinic 4C pyrrhotite (Fe7S8) is the only iron sulphide with high relevance for palaeomagnetism and rock magnetism that can be identified in materials by its characteristic low-temperature anomaly. Despite natural many magnetic studies over last decades, physics crystallography behind this anomaly, also denoted Besnus transition, a matter of debate. In study, we analys...

Once segmentation of 3D surface data of a rock pile has been performed, the next task is to determine the visibility of the surface rocks. A region boundary-following algorithm that accommodates irregularly spaced 3D coordinate data is presented for determining this visibility. We examine 3D surface segmentations of laboratory rock piles and determine which regions in the segmentation correspon...

Submitted for the (l@ annual conference on Magnetism and Magnetic Materials, To be Published in the Journal of Applied Physics, San Jose, Ca.liforni%November 15-18,1999